Objective To investigate the diagnostic value of serum CYS-S and CRP markers in patients with renal damage caused by essential hypertension. Methods 100 cases of primary hypertension were selected and treated in our hospital from February 2017 to February 2018 and set up as observation group. According to the urinary albumin excretion rate (UAEP), 40 cases of normal albuminuria group, 35 cases of microalbuminuria group and 25 cases of albuminuria group were divided, and 40 volunteers who were selected to the hospital for health examination in the same period were set as control. The serum CYS-C and CRP indexes were detected respectively, and the difference between the observation group and the control group was compared. Results The values of CYS-S and CRP in the observation group were all higher than those in the control group, and the difference was statistically significant (P<0.05). In the observation group, the levels of CYS-S and CRP in the microalbuminuria group were higher than those in the normal proteinuria group, but lower than those in the large proteinuria group, and the differences were statistically significant (P<0.05). Compared with CYS-C and CRP, the normal proteinuria group and the microalbuminuria group were detected. The sensitivity of the two indexes was higher, and the difference was statistically significant (P<0.05). Conclusion The serum CYS-C and CRP are important detection indexes for the patients with hypertension and renal damage. The two combined use can significantly enhance the diagnostic sensitivity and have a very positive effect.